Method for dual manufacture of reclosable bags on HFVF machine

ABSTRACT

A method for dual manufacture of reclosable packages on a horizontal-form, vertical fill machine. The method comprising the following steps: extending a web of bag making film under tension in a machine direction; joining one zipper tape to the web along a first zone of joinder generally aligned with the machine direction; joining another zipper tape to the web along a second zone of joinder generally parallel to the first zone of joinder and spaced apart therefrom; and folding the web in first, second and third mutually parallel zones extending in the machine direction. The first zone of folding is disposed between a first edge of the web and the one zipper tape, the second zone of folding is disposed between the two zipper tapes, and the third zone of folding is disposed between the other zipper tape and a second edge of the web. The resulting folded web with attached zippers has a generally W-shaped profile. The two halves of the W-shaped web are cross-sealed, filled, and then top-sealed to form respective chains of filled receptacles. The completed packages are then severed from the respective chains of receptacles.

BACKGROUND OF THE INVENTION

[0001] This invention generally relates to reclosable packaging andmethods for manufacturing reclosable packaging. In particular, theinvention relates to the manufacture of reclosable packages on ahorizontal-form, vertical fill (HFVF) machine.

[0002] Reclosable bags are finding ever-growing acceptance as primarypackaging, particularly as packaging for foodstuffs such as cereal,fresh vegetables, snacks and the like. Such bags provide the consumerwith the ability to readily store, in a closed, if not sealed, packageany unused portion of the packaged product even after the package isinitially opened. To gain acceptance as a primary package forfoodstuffs, it is virtually mandatory that the package exhibit some formof tamper evidence to protect the consumer and maintain thewholesomeness of the contained product. In addition, in many cases it isnecessary that food product be hermetically packaged.

[0003] Reclosable fastener assemblies are useful for sealingthermoplastic pouches or bags. Such fastener assemblies typicallyinclude a plastic zipper and a plastic slider. Typically, the plasticzippers include a pair of interlockable profiled members that fastentogether to form a closure. As the slider moves across the profiles, theprofiles are opened or closed. The profiles in plastic zippers can takeon various configurations, e.g. interlocking rib and groove elementshaving so-called male and female profiles, interlocking alternatinghook-shaped closure members, etc. Reclosable bags having slider-operatedzippers are generally more desirable to consumers than bags havingzippers without sliders because the slider eliminates the need for theconsumer to align the interlockable zipper profiles before causing thoseprofiles to engage.

[0004] Methods and apparatus for manufacturing reclosable plastic bagson form-fill-seal (FFS) machines are well known in the art. The use ofhigh-speed automated equipment to form, fill and seal a reclosablepackage is quite common in the industry.

[0005] One known type of FFS machine is a horizontal-form, vertical fill(HFVF) machine that places slider-zipper tape proximal to a fold in aweb of bag making film, forms receptacles, and then fills thereceptacles through an open package bottom at the top of folded web.This machine typically operates as follows. A pull roller of the HFVFmachine draws a continuous length of bag making film dispensed from asupply roll in a machine direction. As the bag making film is dispensedin the machine direction, a flattening roller positions the film on ahorizontal plane. At the same time, a continuous length of interlockedzipper tape assembly (without sliders) is unwound from a coil and passedthrough a slider insertion device. Also a chain or series of sliders isunwound from a coil or supplied by a vibratory hopper and fed to theslider insertion device. The slider insertion device inserts slidersonto the zipper tape at regular spaced intervals corresponding to thelength of a zipper in each package. The resulting slider-zipper assemblyis placed on the bag making film in alignment with the machinedirection. The continuous length of zipper tape assembly with slidersinserted thereon is longitudinally positioned on the bag making film inparallel with and offset from a line where the film will be folded. At afirst sealing station, one zipper half is permanently sealed to the filmby conduction heat sealing. These permanent seals and the mutualengagement of the zipper profiles maintain the alignment of theslider-zipper assembly with the fold line as the film with attachedslider-tape assembly is drawn around a folder plow or board. The folderplow folds the film lengthwise along the fold line. Optionally, as thebag making film is fed over the folder plow, a perforator perforates thefilm below the interlocking zipper profiles to form respective parallellines of preferential tearing, where a bag header can be torn off of thepackage. At a second sealing station, the other zipper half ispermanently sealed to the bag making film. At the next station, theopposing walls of the bag making film are cross sealed along a zonetransverse to the direction of film movement, the seal zone havingsufficient width to form respective side seals on successive packageswhen the seal zone is cut down the middle by a cutter. The cross sealsform discrete receptacles that can be filled before or after the cuttingstation. After filling, the opposing top edges of the folded web(representing the bottom of the packages) are sealed together at anothersealing station, forming a bottom seal. If the bags have been filledbefore the cutting station, the bag making film is then cut along a sideseal to separate the filled package from the web of bag making film.

[0006] In accordance with variations of the foregoing machine, theslider-zipper tape assembly can be attached proximal to the top edge ofthe folded web, i.e., opposite the fold, and the package can be filledeither by moving the slider to open the zipper (when both zipper halvesare sealed to the film) or by separating the slider-zipper tape assemblyfrom an adjacent unsealed wall of the bag making film, filling thereceptacle through the resulting gap, and then sealing the unsealed filmwall to the slider-zipper tape assembly. Similar methods of manufacturecan be used to make zippered bags that do not have sliders for operatingthe zipper.

[0007] There is a need for a method of manufacture and an apparatus forincreasing the production capacity of such HFVF machines.

BRIEF DESCRIPTION OF THE INVENTION

[0008] The invention is directed to dual manufacture of reclosablepackaging on a horizontal form, vertical fill (HFVF) machine. Theaspects of the invention, some of which are set forth in greater detailimmediately hereinafter, include both methods and apparatus for dualmanufacture of reclosable packages, as well as the transitory article ofmanufacture that is a precursor to the final reclosable packages. Thebasic concept has application in the manufacture of zippered bags withor without sliders.

[0009] One aspect of the invention is an article of manufacturecomprising: a web of bag making film folded under tension along first,second and third folds, the folded web reversing its direction along thefolds to form a serpentine cross-sectional profile with first throughfourth walls, the second wall being disposed between the first and thirdwalls, the third wall being disposed between the second and fourthwalls, a bottom of the first wall being connected to a bottom of thesecond wall along the first fold, a top of the second wall beingconnected to a top of the third wall along the second fold, and a bottomof the third wall being connected to a bottom of the fourth wall alongthe third fold, a first zipper tape having a portion disposed betweenthe first and second walls of the web, and joined to at least one of thefirst and second walls; and a second zipper tape having a portiondisposed between the third and fourth walls of the web, and joined to atleast one of the third and fourth walls. Each of the first and secondzipper tapes comprises first and second mutually interlockable portionsin an interlocked state. These zippers may be opened and closed bysliders preloaded on the zippers.

[0010] Another aspect of the invention is a method of manufacturing anarticle, comprising the following steps: extending a web of bag makingfilm under tension in a machine direction; joining a first zipper tapeto the web along a first zone of joinder generally aligned with themachine direction; joining a second zipper tape to the web along asecond zone of joinder generally parallel to the first zone of joinderof the first zipper tape and spaced apart therefrom; and folding the webin first, second and third mutually parallel zones extending in themachine direction, the first zone of folding being disposed between afirst edge of the web and the first zipper tape, the second zone offolding being disposed between the first and second zipper tapes, andthe third zone of folding being disposed between the second zipper tapeand a second edge of the web. As used herein and in the claims, the term“zone of folding” encompasses both a line of folding and a gradual foldthat spans a band-shaped zone. These zippers may be opened and closed bysliders preloaded on the zippers.

[0011] A further aspect of the invention is an article of manufacturecomprising: a web of bag making film folded under tension along first,second and third folds, the folded web reversing its direction along thefolds to form a serpentine cross-sectional profile with first throughfourth walls, the second wall being disposed between the first and thirdwalls, the third wall being disposed between the second and fourthwalls, a bottom of the first wall being connected to a bottom of thesecond wall along the first fold, a top of the second wall beingconnected to a top of the third wall along the second fold, and a bottomof the third wall being connected to a bottom of the fourth wall alongthe third fold, and a zipper strip comprising a base having a firstportion joined to the second wall and a second portion joined to thethird wall, wherein the base is folded and wrapped around the secondfold of the web. The zipper strip further comprises first and secondprofiled closure members supported by the base and generally parallel toeach other, the first profiled closure member being disposed between thefirst and second walls of the web, and the second profiled closuremember being disposed between the third and fourth walls of the web.

[0012] Yet another aspect of the invention is a method of manufacturingan article, comprising the following steps: extending a web of bagmaking film under tension in a machine direction; joining a zipper stripto the web along a zone of joinder generally aligned with the machinedirection, the zipper strip comprising a base joined to the web, andfirst and second profiled closure members supported by the base andgenerally parallel to each other; and folding the web and the base ofthe zipper strip along a zone of folding that overlaps a central portionthe zone of joinder, the first and second profiled closure members beingdisposed on opposite sides of the zone of folding.

[0013] A further aspect of the invention is an integrally formed hingedzippered structure comprising first and second profiled closure members,first and second hinge lines, a first web having one end connected tothe first closure member and another end connected to the first hingeline, a second web having one end connected to the second closure memberand another end connected to the second hinge line, and a third webhaving one end connected to the first hinge line and the other endconnected to the second hinge line. These zippers may be opened andclosed by sliders preloaded on the zippers.

[0014] Another aspect of the invention is an integrally formed zipperedstructure comprising a web and first through fourth profiled closuremembers connected to the web, the first through fourth closure membersbeing disposed generally in parallel with each other, the first closuremember being interlocked with the second closure member, and the thirdclosure member being interlocked with the fourth closure member. The webcomprises first and second web portions connected by a third webportion. The first web portion comprises a first zone connected to thefirst closure member and a second zone connected to the second closuremember, while the second web portion comprises a third zone connected tothe third closure member and a fourth zone connected to the fourthclosure member.

[0015] Yet another aspect of the invention is a method of manufacturingan article, comprising the following steps: extending a web of bagmaking film under tension in a machine direction; folding the web infirst, second and third mutually parallel zones extending in the machinedirection, the folded web reversing its direction along the zones offolding to form a serpentine cross-sectional profile with first throughfourth walls, the second wall being disposed between the first and thirdwalls, the third wall being disposed between the second and fourthwalls, a bottom of the first wall being connected to a bottom of thesecond wall along the first fold, a top of the second wall beingconnected to a top of the third wall along the second fold, and a bottomof the third wall being connected to a bottom of the fourth wall alongthe third fold; inserting at least a portion of a first zipper tapebetween the first and second walls of the folded web; inserting at leasta portion of a second zipper tape between the third and fourth walls ofthe folded web; joining the first zipper tape to at least one of thefirst and second walls; and joining the second zipper tape to at leastone of the third and fourth walls. These zippers may be opened andclosed by sliders preloaded on the zippers.

[0016] A further aspect of the invention is a machine for forming,filling and sealing a folded web of bag making film, the folded webhaving a serpentine cross-sectional profile comprising first and secondfolded portions in respective upright positions and open at the tops,and a central inverted folded portion extending in a machine direction,the central inverted folded portion connecting the first folded portionto the second folded portion. The machine comprises: an upright saddlehaving a generally constant profile in the machine direction, whereinthe central inverted folded portion of the web is supported by thesaddle and slides along the saddle as the web advances in the machinedirection. means for cross sealing the first and second folded portionsof the web at regular spaced intervals to form respective first andsecond series of open receptacles; means for filling successivereceptacles of the first and second series concurrently; and means forsealing successive filled receptacles of the first and second seriesclosed.

[0017] Other aspects of the invention are disclosed and claimed below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 is a drawing showing a sectional view of a precursorarticle in accordance with one embodiment of the invention. This view(as well as the views of FIGS. 2-9, 13-15, and 17) is taken at anintermediate stage in the dual manufacture of reclosable packages on aHFVF machine.

[0019]FIG. 2 is a drawing showing a sectional view of the precursorarticle of FIG. 1 after a further folding step.

[0020]FIG. 3 is a drawing showing a sectional view of a precursorarticle in accordance with another embodiment of the invention.

[0021]FIG. 4 is a drawing showing a sectional view of the precursorarticle of FIG. 3 after a further folding step. Structural variationsare depicted in dashed or dotted lines.

[0022]FIG. 5 is a drawing showing a sectional view of a precursorarticle in accordance with a further embodiment of the invention.

[0023]FIG. 6 is a drawing showing a sectional view of the precursorarticle of FIG. 5 after a further folding step.

[0024]FIG. 7 is a drawing showing a sectional view of a precursorarticle having a hinged zipper in accordance with a further embodimentof the invention.

[0025]FIG. 8 is a drawing showing a hinged zipper construction inaccordance with the embodiment shown in FIG. 7.

[0026]FIG. 9 is a drawing showing the hinge of the hinged zipper of FIG.8 in detail.

[0027]FIG. 10 is a drawing showing a sectional view of a precursorarticle in accordance with another embodiment of the invention, the viewbeing taken before the web of bag making film is folded.

[0028]FIG. 11 is a drawing showing a sectional view of the precursorarticle of FIG. 8 after the web of bag making film has been folded.

[0029]FIG. 12 is a drawing showing a top plan view of a stage in amethod of manufacturing yet another embodiment of the invention. For thesake of illustration, it has been assumed that the bag making film isoptically transparent, so that structural features disposed under thefolded film are visible. The manufacturing stage depicted in FIG. 12precedes the step wherein the web of bag making film is folded along acentral zone.

[0030]FIGS. 13 and 14 are drawings respectively showing side elevationaland top plan views of a later stage in the method of manufacturepartially depicted in FIG. 12. The manufacturing stage depicted in FIGS.13 and 14 is subsequent in time to the step wherein the web of bagmaking film is folded along a central zone.

[0031] FIGS. 15-18 are drawings showing respective sectional views ofthe machine depicted in FIG. 13, the sections being taken along thelines designated 15-15, 16-16, 17-17, and 18-18 respectively in FIG. 13.

[0032]FIG. 19 is a drawing showing a side elevational view of avariation of the method of manufacture depicted in FIG. 13.

[0033]FIG. 20 is a drawing showing a sectional view of a precursorarticle provided with peel seals in accordance with yet anotherembodiment of the invention.

[0034]FIG. 21 is a drawing showing a method for attaching flanged zipperassemblies inside the folds of a doubly folded web of bag making film.

[0035]FIG. 22 is a drawing showing a method for attaching string zipperassemblies inside the folds of a doubly folded web of bag making film.

[0036]FIG. 23 is a drawing showing a top view of the zipper sealingarrangement being used in FIG. 22.

[0037] Reference will now be made to the drawings in which similarelements in different drawings bear the same reference numerals.

DETAILED DESCRIPTION OF THE INVENTION

[0038] In accordance with the embodiments of the invention disclosedherein, successive pairs of reclosable packages are manufactured usingonly one web of bag making film, the bags of each pair beingmanufactured side-by-side and concurrently. The process starts withunwinding a web of bag making film from a roll and threading it througha form-fill-seal machine. Coming off of the roll, the web is pulledunder tension in a generally horizontal plane. The tensioned film isfolded along three mutually parallel lines or zones to form a generallyW-shaped profile, as will be described in more detail below. Zippers fortwo lines of bags are attached to the bag making film before or afterfolding or in between separate folding operations. The two halves of thetriply folded web of bag making film are then cross-sealed at regularintervals to form a chain or series of receptacles. Successive pairs ofreceptacles—one receptacle from each chain—are filled with product. Thenthe open ends of the filled bags are closed. The dual manufacture ofreclosable packages doubles the capacity of a form-fill-seal machine.

[0039] The bag making film may be made of a suitable plastic filmmaterial for the product to be contained within the package. Forexample, the film may be a laminate or coextrusion comprising a gasbarrier layer and/or a low-melting-point sealant layer. The zipperstrips are sealed to the bag making film by permanent seals. It shouldbe appreciated that each permanent seal is a band of joined, e.g.,fused, material that extends from one side seal of the bag to the otherside seal, thereby securing the zipper to the bag along the width of thebag. The permanent seals are generally parallel to each other and may beformed by any conventional method, such as conduction heat sealing. Theinvention has application with both slider-operated and sliderlesszippered bags. In the former case, the slider is mounted to the profiledclosure members of the zipper to facilitate zipper opening and closingin a well-known manner. For proper functioning, the interlockableclosure members may have spot seals or ultrasonic stomps at the ends ofthe zipper halves. These seals ensure the zipper strips will not comeapart during use and provide end stops for stopping the slider. Theslider 8 is preferably made of a resilient plastic material, such asdelrin, polypropylene, PBT, etc. Prior to opening of the package by theconsumer, the slider-zipper assembly is frequently covered on theconsumer side by an enclosed header that is hermetically sealed. Thesealed header provides a tamper-evident feature. Peel seals below orabove the zippers may also be provided.

[0040]FIGS. 1 and 2 show one embodiment of the invention at two stagesin the manufacturing process. Two zipper tapes are installed inrespective folds of a folded web of bag making film. The zippers are ofthe webless or so-called “string” variety, meaning that they do not havewebs or flanges extending to one side of the profiled closure members.However, sliderless webbed zippers may also be used. A webless or stringzipper is attached to bag making film in the base areas of theinterlocking closure elements. FIG. 1 shows the intermediate stage afterthe following steps have been performed: (1) a pair of zipper tapes 4and 4′ are placed atop a flat tensioned web 2 of bag making film alignedwith the machine direction (out of the page); (2) the bases of thezipper strips 18 and 18′ are sealed or otherwise joined to the web 2along parallel bands or zones; (3) the web 2 is folded along lines orzones parallel to the foregoing zones of zipper strip joinder to formfolds 6 and 6′, with the folded portions of the web respectivelyoverlying the zipper tapes 4 and 4′; and (4) the folded portions of web2 are sealed or otherwise joined to the bases of the zipper strips 20and 20′ of the respective zipper tapes. Although FIG. 1 depicts a gapseparating the edges of the folded portions of the web of bag makingfilm, the edges may meet or overlap each other. In FIG. 1, the profiledclosure members of the zipper tapes are depicted as having male andfemale profiles. However, the profiles of the interlocking closureelements need not be of the male/female variety. Any type ofinterlocking elements, e.g., interlocking hooks, may be utilized.

[0041] The precursor structure shown in FIG. 1 is folded along a centralzone 8 to form the triply folded structure depicted in FIG. 2. It shouldbe noted that the central fold 8 is formed by folding the bag makingfilm in a direction opposite to that by which folds 6 and 6′ wereformed. As seen in FIG. 2, the folded web 2 reverses its direction alongthe folds 6′, 8 and 6 to form a serpentine cross-sectional profile withfirst and second walls 10 and 12 on one side of central fold 8, andthird and fourth walls 14 and 16 on the other side of the central fold8. The bottoms of walls 10 and 12 are connected along fold 6; the topsof wall 12 and 16 are connected along central fold 8; and the bottoms ofwalls 14 and 16 are connected along fold 6′. The zipper tape 4 isdisposed between walls 10 and 12 near fold 6, while the zipper tape 4′is disposed between walls 14 and 16 near fold 6′. In the configurationshown in FIG. 2, both sides of the W-shaped structure can becross-sealed (not shown) and then filled through the open bottoms of thereceptacles formed by cross sealing, i.e., the interior volumes of thereceptacles are filled behind the zippers. Then the bottoms of thepackages are sealed and a cut 56 is made in fold 8 to sever each pair offilled packages from each other. The respective filled packages at thetermini of the respective chains of packages are then severed from therespective chains to form a pair of severed completed packages (notshown).

[0042] In the embodiment depicted in FIGS. 1 and 2, the zipper tapeswere placed on the flat web of bag making film at locations proximal tothe outer zones of folding, giving rise to the precursor structure ofFIG. 2 in which the zipper tapes are situated near the bottoms of theU-shaped web troughs. The folded portions 6 and 6′ of bag making filmserve as headers that provide evidence of tampering with the package.Although not shown in FIG. 2, lines of weakness (such as perforation orlaser score lines) can be provided in conventional fashion to aid thetearing away of the header, thereby allowing access to the zipperinside.

[0043] Alternatively, the zipper strips can be placed proximal to and onopposite sides of the central folding zone, so that the zipper tapeswill be situated near the tops of the troughs and adjacent to thecentral fold 8. In accordance with another method of manufacture, thefolded portions of central fold 8 and the outer edges or adjacent areaof the web are sealed to the adjoining zipper strips, in which case thezippers must later be opened in order to fill the receptacles formed bycross sealing. This can be accomplished by separating the zipper stripsand adjoining web portions, e.g., by means of a separating finger orplow positioned between the zipper strips. In accordance with anothermethod of manufacture, the outer edges of the web are not sealed to theadjoining zipper strips, in which case the receptacle formed later bycross sealing can be filled by pulling the opposing edges of thefolded-over web portions away from the zipper tapes and filling thereceptacle through the gaps between the web portions and the zippertapes. Alternatively, if the zippers are slider operated, then thesliders may be used to open the zipper for filling the receptacle andclosing it thereafter.

[0044] In accordance with yet another variation, the zipper strips ofthe respective zipper tapes can be separately joined to the web of bagmaking film. One pair of zipper strips are sealed in parallel to themachine direction at respective locations proximal to and on oppositesides of the central folding zone, while another pair of zipper stripsare sealed in parallel to the first pair of zipper strips at locationsproximal to the edges of the web of bag making film. On each half of theweb, the inner and outer zipper strips are equidistant from the locationwhere that half of the web will be folded over. In this case the web isfolded on both sides and then the zipper strips at the web edges areinterlocked with the more centrally located zipper strips. In accordancewith a further variation, instead of joining four separate zipper stripsto the web of bag making film, the profiled closure members can beintegrally formed with the bag making film, e.g., by extrusion. In yetanother variation, the zipper strips are sealed to the folded web insidethe web folds at the same time. In such an instance, separating platesmay be inserted between the zipper strip flanges to preventseal-through.

[0045]FIGS. 3 and 4 depict precursor structures for reclosable packagingcomprising slider-operated zippers installed at the open tops of theU-shaped folded portions of the web 4. The sliders 25 can be insertedbefore the zipper tapes 22 and 22′ are attached to the web 4 of bagmaking film or after zipper attachment and folding of the web. Eachzipper tape comprising a pair of interlocked zipper strips. For zippertape 22, one zipper strip comprises a profiled closure member 24 and aflange 28 having one end connected thereto, and the other zipper stripcomprises a profiled closure member 26 and a flange 30 having one endconnected thereto. For zipper tape 22′, one zipper strip comprises aprofiled closure member 25 and a flange 32 having one end connectedthereto, and the other zipper strip comprises a profiled closure member27 and a flange 34 having one end connected thereto. The profiles of theclosure members may have any known configuration, e.g., male/female,interlocking hooks, etc.

[0046]FIG. 3 shows the intermediate stage after the following steps havebeen performed: (1) a pair of zipper tapes 22 and 22′ are placed atop aflat tensioned web 2 of bag making film aligned with the machinedirection; (2) the flange 30 of one zipper strip and the flange 34 ofthe other zipper strip are sealed or otherwise joined to the web 2 alongparallel bands or zones; (3) the web 2 is folded along lines or zonesparallel to the foregoing zones of flange joinder to form folds 6 and6′, with the folded portions of the web respectively overlying thezipper flanges 28 and 32; and (4) the folded portions of web 2 aresealed or otherwise joined to the zipper flanges 28 and 32. AlthoughFIG. 3 depicts the edges of the folded portions of the web of bag makingfilm as not extending beyond the zipper flanges to which they areattached, the folded portions of the web may extend beyond the zippertapes for later use in the formation of tamper-evident headers for thepackages (as will be described later with reference to FIG. 20).Alternatively, zipper tapes 22 and 22′ can be introduced between thealready folded film with flanges 28, 30 and 32,34 being sealed at thesame time to the respective film web areas. In such an instance,separating plates may be positioned between mutually opposed flanges toprevent seal-through, as will be described in more detail later withreference to FIG. 21.

[0047] The precursor structure shown in FIG. 3 is folded along a centralzone 8 to form the triply folded structure depicted in FIG. 4, thefolding operation being substantially similar to that previouslydescribed in connection with FIG. 2. As seen in FIG. 4, the folded web 2reverses its direction along the folds 6′, 8 and 6 to form a serpentinecross-sectional profile similar to that previously described withreference to FIG. 2, with first and second walls 10 and 12 on one sideof central fold 8, and third and fourth walls 14 and 16 on the otherside of the central fold 8. The zipper tapes 22 and 22′ with sliders 25project upward on opposite sides of the central fold 8 of the invertedU-shaped precursor structure.

[0048] In the configuration shown in FIG. 4, both sides of the W-shapedstructure can be cross-sealed to form individual receptacles. The slideron each zipper segment corresponding to a receptacle to be filled isthen mechanically moved from the closed position to the open position,thereby opening the formed receptacle for filling. The interior volumesof the receptacles are filled through the open zippers. The sliders arethen used to close the zipper. Alternatively, the slider is keptstationary and the zipper is moved through the slider to open it beforefilling and is then mechanically closed after filling. Then the zippersare closed. Following the filling operation, the two chains of filledreceptacles are advanced one package increment. During this advance, acut 56 is made in fold 8 to sever the pair of filled packages at thetermini of the chains from each other. The respective filled packages ofthis terminal pair are then severed from the respective chains to form apair of severed completed packages.

[0049] Any of the packages disclosed herein can be provided withtamper-evident features, such as a peel seal inside the interior of thepackage. For the purpose of illustration, alternative tamper-evidentfeatures are shown in FIG. 4. In accordance with a first alternative,opposing zipper flanges of each zipper tape may be sealed together by arespective peel seal 90, indicated by small dashed rectangles in FIG. 4.The peel seal material can be applied on one of the zipper flangesbefore the zipper tapes are joined to the bag making film. The peel sealcan be formed by pressing the zipper flanges together while applyingsufficient heat to activate the peel seal material. Such a peel sealmust be broken or ruptured in order to gain access to the interiorvolume of the package, thereby leaving evidence that warns a consumerthat the package has been tampered with. In accordance with a secondalternative, the zipper flanges of each zipper tape may be connected byan integrally formed web or membrane 52, which is indicated by dottedcurved lines in FIG. 4. In this case, each web 52 has a line of weakness(not shown) to facilitate tearing or rupture of the web in a preferreddirection generally parallel to the zipper.

[0050] In accordance with further alternatives, the final packages canbe provided with headers that form enclosed volumes above the zippers toprevent tampering with the contents of the package. In the case of theembodiment depicted in FIG. 4, respective header webs can be folded overand attached to the tops of the respective chains of receptacles aftercutting along line 56. Alternatively, the web of bag making film is wideenough and the zipper tapes are positioned such that after cutting alongline 56, the edges of the web of bag making film can be sealed togetherto form respective headers over the zippers. Instead of the bag makingfilm being sealed to itself at the apex of the header, a strip of peelseal material could be placed between the opposing edges of the web tojoin them together, as will be described in more detail later withreference to FIG. 20. The foregoing header configurations have equalapplication in the context of the other embodiments described below inwhich the zippers are installed at the tops of the folded web and not inthe folded bottoms of the web of bag making film.

[0051] In connection with the embodiment of FIGS. 1 and 2, a variationwas described in which the zipper tapes would be placed on the web ofbag making film along mutually parallel zones located proximal to and onopposite sides of the central folding zone. FIG. 5 shows a furthervariant wherein two of the four zipper strips are connected to form azipper strip 36 having two mutually parallel profiled closure membersprojecting from the same side of an extended base. Each closure memberon strip 36 is interlocked with a respective complementary closuremember of a respective zipper strip 20 or 20′. The strip 36 (carryinginterlocked strips 20 and 20′) is sealed or otherwise joined to acentral zone of the web 2 of bag making film and then the outer sectionsof the web are folded over the zipper strips 20 and 20′ and sealedthereto. [Alternatively, the zipper strips 20 and 20′ could be joined tothe web 2 near the edges of the latter and then interlocked with theclosure members of strip 36 when the outer sections of the web arefolded over.] The result of these method steps is depicted in FIG. 5.Then the web 2 and strip 36 are folded in the middle to form fold 8, asseen in FIG. 6, the folding action being in a direction opposite to thatof folds 6 and 6′. While in the upright position shown in FIG. 6, bothU-shaped halves of the folded web of bag making film are cross sealed toform respective chains or series of receptacles. The zippers of eachsuccessive pair of side-by-side receptacles can be opened to enable thereceptacles to be filled. Again, this can be accomplished by separatingthe zipper strips 20 and 20′ and adjoining strip 36 e.g., by means of aseparating finger positioned between the strips, as will be described inmore detail later with reference to FIGS. 22 and 23. Then the respectivezippers on the most recently filled pair of receptacles are closed andthe projecting top edges of the bag making film can be sealed togetherto form headers over the zippers in conventional manner. Then thecompleted packages can be severed from the respective chains ofreceptacles by transverse cutting, as previously described.

[0052] In accordance with an alternative method of manufacture, theedges or adjacent area of the folded-over portions of the web are notsealed to the zipper strips 20 and 20′ until after filling, in whichcase the receptacle formed later by cross sealing can be filled bypulling the opposing edges of the folded-over web portions away from theadjoining zipper strips and filling the receptacle through the gapsbetween the web portions and the zipper strips. Thereafter the adjacentportions of the bag making film are sealed or otherwise joined to thezipper strips 20 and 20′.

[0053]FIG. 7 depicts another embodiment of a precursor structure inwhich respective parts of two zipper tapes (with sliders 25 insertedthereon) are connected by an integrally formed web or membrane 38,forming a hinged zipper assembly. As best seen in FIG. 8, one end of theweb 38 and one end of a zipper flange 34 are connected at a first hingeline 36′, while the other end of the zipper flange 34 is connected to aprofiled closure member of one slider-operated zipper 22′. The other endof the web 38 and one end of a zipper flange 30 are connected at asecond hinge line 36′, while the other end of the zipper flange 30 isconnected to a profiled closure member of the other slider-operatedzipper 22. This zipper structure is integrally formed. Each hinge linemay comprise a corner section having necked or narrowed segments thatmeet at a vertex 37 (see FIG. 9) to form a profile that flexes from arelatively open configuration to a relatively closed configuration asthe hinged zippered structure is bent and folded into the generallyW-shaped configuration seen in FIG. 7.

[0054] The central web 38 is sealed or otherwise joined to a centralzone of the web of bag making film and then folded as shown to form thecentral inverted fold 8. In addition, a pair of zipper strips, eachcomprising a profiled closure member and a zipper flange having one endconnected to the profiled closure member, is attached to parallel outerportions of the web of bag making film. The zipper strips are locatedand oriented so that when the outer section of the web are folded over,the closure members of the zipper strips can be interlocked with theclosure members of the central zippered structure, as seen in FIG. 8.The zipper flange 28 of one zipper strip is sealed to a portion of theweb that becomes part of wall 14, while the zipper flange 32 of theother zipper strip is sealed to a portion of the web that becomes partof wall 10. In this embodiment, the receptacles formed by cross sealingcan be opened by mechanically moving the sliders relative to the zippersand then the open receptacles are filled. Then the zippers of the filledreceptacles can be closed, again by mechanically moving the slider, andseparate filled packages can be severed from the respective chains bycutting. Alternatively, as indicated previously, the slider can bestationary while the zipper is moved through the slider to open thereceptacle.

[0055] In accordance with a variation of the embodiment shown in FIG. 7,the opposing zipper flanges of each zipper can be connected by anintegrally formed web or membrane 52, indicated by dashed curved linesin FIG. 7. These webs or membranes provide a tamper-evident feature.

[0056]FIGS. 10 and 11 depict an embodiment of the invention wherein theentire double-zippered structure 40 is integrally formed. The integrallyformed zippered structure 40 comprises a web 42 and first through fourthprofiled closure members connected to the web 42. The closure membersare disposed generally in parallel with each other, the first closuremember 48 being interlocked with the second closure member 44, and thethird closure member 50 being interlocked with the fourth closure member46. The web 42 comprises first and second web portions connected by athird web portion. In the particular example depicted in FIG. 10, thethird web portion extends from the base of the male closure member 48 tothe base of the male closure member 50. The first web portion extendsfrom one zone connected to closure member 44 to another zone connectedto the closure member 48 (and to the third web portion), while thesecond web portion extends from one zone connected to closure member 46to another zone connected to closure member 50 (and to the third webportion). The double-zippered structure 40 can be made by extruding aplanar web with the four profiled closure members running in parallel atspaced intervals along the length of the web. Then the outer sections ofthe web are folded over and the opposing closure members are interlockedas seen in FIG. 10. Before folding, two lines of weakness 54 can beformed in the web, the lines of weakness being placed on the web suchthat they lie at the cusp of the folds when the web 42 is folded. Eachline of weakness may comprise a line of perforations covered by a thinsealing strip or a score line formed by a laser beam.

[0057] As seen in FIG. 10, the spine of the zippered structure 42 issealed or otherwise joined to a flat web 2 of tensioned bag making film.The zippered structure 42 can be joined along one or more zones ofjoinder. Multiple zones of joinder are mutually parallel. The resultingstructure is then folded three times along mutually parallel zones offolding 6, 6′ and 8, to arrive at the configuration shown in FIG. 11.After the outer sections of web 2 are folded over to form folds 6 and6′, the folded-over web portions overlapping zipper closure members 44and 46 are not yet joined to the respective adjacent portions of zipperweb 42. Before or after the aforementioned folding steps, the centralportions of the web 2 of bag making film and the zipper web 42 arefolded in the opposite direction to form an inverted (i.e., upside down)U shape that connects the U shapes formed by folds 6 and 6′. While inthe upright position shown in FIG. 11, both U-shaped halves of thefolded web of bag making film 2 first have their outer sections sealedto the adjacent portions of zipper web 42 and then are cross sealed toform respective chains or series of receptacles. The zippers of eachsuccessive pair of side-by-side receptacles can be opened to enable thereceptacles to be filled. Again, this can be accomplished by separatingclosure member 44 from 48 and closure member 46 from 50 by means of aseparating finger. In accordance with another method of manufacture, thefolded-over portions 6 and 6′ of the web are not sealed to the adjoiningzipper strips 20 and 20′ until after filling, in which case thereceptacles subsequently formed by cross sealing can be filled bypulling the opposing edges of the folded-over web portions away from theadjoining zipper strips and filling the receptacle through the gapsbetween the web portions and the zipper strips. In either case, afterthe filling operation, the respective chains of receptacles are severedfrom each other and then respective completed packages are severed fromthe respective chains of receptacles. Optionally, tamper-evident headerscan be made (in any one of the ways previously described) before thecutting operations.

[0058] In accordance with an alternative embodiment, the webless zippersof the embodiment shown in FIG. 2 can be replaced by flanged zippersoperated by sliders, the latter being placed upside down proximal to thebottom folds in the generally W-shaped folded web of bag making film.The zipper tapes with sliders can be joined to the web of bag makingfilm either before or after folding of the bag making film. Toillustrate one embodiment of a dual-capacity HFVF machine, theembodiment wherein the zipper tapes are joined to the web of bag makingfilm before folding will now be described with reference to FIGS. 12-18.

[0059]FIG. 12 depicts a flat horizontal web 2 of bag making film beingfolded along a pair of parallel fold lines 6 and 6′ as it advances in amachine direction. This can be accomplished using a folding board (notshown). The web 2 entering this folding station carries two zipper tapes22 and 22′, each zipper tape having a multiplicity of sliders 25inserted thereon. The sliders 25 are spaced at equal intervals, oneslider for each length of bag making film equal to the width of thefinal package. In this example, each zipper strip of the respectivezipper tapes comprises a respective profiled closure member and arespective zipper flange having one end connected to the respectiveclosure member. The closure members of each zipper tape havecomplementary mating profiles. In the top view of FIG. 12, only zipperflanges 28 and 32 of zipper tapes 22 and 22′ are visible, although itshould be understood the a respective lower zipper flange lies directlybelow the zipper flanges 28 and 32. At a first sealing station, a lowersealing bar (not visible in FIG. 12) and an upper pressure plate 60located directly above the lower sealing bar and between the zipperflanges apply pressure and conductive heat to seal the lower zipperflange (not visible) of zipper tape 22 to the web 2, while another upperpressure plate 60′ and another lower sealing bar (not visible in FIG.12) located directly below upper pressure plate 60′ apply pressure andconductive heat to seal the lower zipper flange (not visible) of zippertape 22′ to the web 2. In this example, the zipper tapes are alignedwith the machine direction and disposed between the fold lines 6 and 6′with zipper flanges pointing toward the center of the web 2. Ultimately,the fold lines 6 and 6′ will form the apices of headers on the tops ofthe final packages. Immediately after the first sealing station, theouter sections of the web 2 of bag making film are folded over thezipper tape, as seen in FIG. 12. For the purpose of this example, it isassumed that the bag making film is optically transparent, so that theportions of the zipper tape lying underneath the folded-over portions ofthe web 2 are visible in FIG. 12. At a second sealing station, an uppersealing bar 62 and a lower pressure plate (not visible in FIG. 12)located directly below sealing bar 62 and between the zipper flangesapply pressure and conductive heat to seal zipper flange 28 of zippertape 22 to the opposing folded-over portion of web 2, while anotherupper sealing bar 62′ and a lower sealing bar (not visible in FIG. 12)located directly below sealing bar 62′ apply pressure and conductiveheat to seal zipper flange 32 of zipper tape 22′ to the opposingfolded-over portion of web 2. The web of bag making film then advancesto the next station.

[0060] At the next station, the web 2 of bag making film is convertedfrom a horizontal position to a vertical position. In the process, theweb 2 is folded along a centerline to form the generally W-shapedprofile shown in FIG. 15. More specifically, the web 2 is folded againstand wrapped around an upright support plate 82, which preferably has aprofile comprising substantially mutually parallel planar side walls,the surfaces of which are connected by a circular semi-cylindricalsurface at the upper end of the support plate. The axis of the semicylindrical surface of support plate 82 is aligned in the machinedirection, i.e., the direction in which the web of bag making filmadvances during this stage of manufacture.

[0061] Referring to FIGS. 13 and 14, the folded web 2 with zipper tapesattached and with sliders 25 inserted at spaced intervals along thezipper tapes is pulled forward by a pair of upright grooved drive rolls64 arranged in opposition to opposing side walls of the support plate82. Respective portions of the generally W-shaped web pass betweenrespective nips formed between the drive rolls 64 and the support plate82 disposed therebetween. The annular grooves in the drive rolls 64 havea width greater than the height of the sliders 25 and are verticallypositioned to allow the sliders to pass through the grooves when the webof bag making film with attached zipper tape is advanced. The hatchedband-shaped area designated 58 indicates the zipper flange-to-filmpermanent seals formed at the first and second sealing stations,previously described.

[0062] At a third sealing station, a vertical sealing bar 66 and avertical sealing bar (not visible in FIG. 10) located directly behindsealing bar 66 apply sufficient pressure and conductive heat to formtransverse or cross seals 76 at spaced intervals along the length of theweb. Each cross seal 76 is a band-shaped zone, which is subsequentlybisected when the completed package is severed from the chain, therebyforming side seals on two packages. The cross seals in combination withthe bottom folds form respective receptacles that are filled at afilling station having a pair of fill tubes or spouts 70. The unsealedends of the respective receptacles at the filling station are openedwider by means of a pair of retractable suction or vacuum-activated cups68. The cups 68 are advanced into position in abutment with the outerwalls of the W-shaped web of bag making film, the suction or vacuum isapplied, and then the cups 68 are retracted while holding the web walls,causing the outer walls to spread outward, as seen in FIG. 14. Theproduct is then poured through the fill tubes 70 and into the respectivereceptacles, as depicted in FIG. 16. When the receptacle is filled withproduct, the vacuum cups are returned to their original positions andthe vacuum is released. Then the filled receptacle is advanced toanother sealing station where the open top of the receptacle (which willbe the bottom of the completed package) is sealed. At the fourth sealingstation, a pair of horizontal sealing bars 72 apply sufficient pressureand conductive heat to form a horizontal seal across the top of the web,thereby closing the respective receptacles. FIG. 17 shows the seal bars72 in their retracted positions. When they are extended, the top edgesof the two separated receptacles are sealed. It should be noted that thesealing bars at the third and fourth stations press the web of bagmaking film against the sides of the support plate 82. After the topsealing operation, the web is advanced. During this advance, the topsealed filled receptacle is cut along the central fold 8 by a knife 84.To advance the receptacles now separated by knife 84, rollers 94 oneither side of the support plate 82, positioned at a slant if sorequired (see FIG. 18), in conjunction with belts 92 under the filledreceptacles, move the receptacles through the fourth sealing station.Additional rollers can be located at different positions in the HFVFmachine either on the sides of the web or above, as indicatedpreviously, to move the web through the other positions. Finally, thecompleted packages are severed from the respective chains of receptaclesby a pair of knives 74 that cut through the center of seal 76 (see FIGS.13 and 14).

[0063] In accordance with an alternative embodiment shown in FIG. 19,the cross seal bars do not reach the top edges of the folded web of filmand the film passes on both sides of each fill spot 70. In this case,the seal bars 72′ are wider. The resulting bottom seal is indicated bythe hatched region designated by the numeral 86.

[0064] In accordance with a further embodiment of the invention,slider-operated zippers can be installed on either side of the centralfold instead of proximal to the outer folds of the generally W-shapedweb 2 of bag making film. This situation is depicted in FIG. 20, whereinnumerals 22 and 22′ designate the respective zipper tapes installedbetween the walls of the folded web. Strips 90 of peel seal material arejoined to one wall of each side of the W-shaped web 2. Before the knife84 severs the two sides of the folded web from each other, thehorizontal seal bars 72 activate the peel seal. FIG. 20 shows the sealbars 72 in the retracted position and the peel seal material 90 not yetactivated.

[0065] In many of the methods of manufacture disclosed hereinabove,zipper strips are attached to the web of bag making film before the webis folded. Alternatively, the web of bag making film can be folded tohave the above-described generally W-shaped serpentine profile and thenthe zipper strips are inserted in between the folded portions and sealedto the web, as shown in FIG. 21, by outside seal bars 72 and opposingseal bars 73 contained within the support plate 82. This is followed bycross sealing, filling and cutting as previously described. In such aninstance, separating plates 96 can be introduced between the zipperflanges to prevent seal through when sealing the flanges to film web 2.If the zippers do not have flanges, being sealed to the film by theirbase, their interlocking elements can be separated by a separating plate98 introduced between the interlocking elements in the sealing area andthen being rejoined by a pair of rollers 100, as shown in FIGS. 22 and23.

[0066] While the invention has been described with reference topreferred embodiments, it will be understood by those skilled in the artthat various changes may be made and equivalents may be substituted formembers thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationto the teachings of the invention without departing from the essentialscope thereof. Therefore it is intended that the invention not belimited to the particular embodiment disclosed as the best modecontemplated for carrying out this invention, but that the inventionwill include all embodiments falling within the scope of the appendedclaims.

[0067] As used in the claims, the verb “joined” means fused, bonded,sealed, adhered, etc., whether by application of heat and/or pressure,application of ultrasonic energy, application of a layer of adhesivematerial or bonding agent, interposition of an adhesive or bondingstrip, etc. As used in the claims, the term “zipper tape” compriseseither a pair of zipper strips comprising respective interlockedprofiled closure members or a monolithic structure comprising a pair ofinterlocked profiled closure members connected by a folded web ormembrane.

1. An article of manufacture comprising: a web of bag making film foldedunder tension along first, second and third folds, said folded webreversing its direction along said folds to form a serpentinecross-sectional profile with first through fourth walls, said secondwall being disposed between said first and third walls, said third wallbeing disposed between said second and fourth walls, a bottom of saidfirst wall being connected to a bottom of said second wall along saidfirst fold, a top of said second wall being connected to a top of saidthird wall along said second fold, and a bottom of said third wall beingconnected to a bottom of said fourth wall along said third fold; a firstzipper tape having a portion disposed between said first and secondwalls of said web, and joined to at least one of said first and secondwalls; and a second zipper tape having a portion disposed between saidthird and fourth walls of said web, and joined to at least one of saidthird and fourth walls, wherein each of said first and second zippertapes comprises first and second mutually interlockable portions in aninterlocked state.
 2. The article as recited in claim 1, wherein each ofsaid first and second zipper tapes further comprises a respective webintegrally formed with said respective first and second mutuallyinterlockable portions.
 3. The article as recited in claim 1, whereineach of said first and second zipper tapes further comprises first andsecond flanges having respective ends connected to said first and secondmutually interlockable portions.
 4. The article as recited in claim 1,further comprising a first multiplicity of sliders mounted to said firstzipper tape and a second multiplicity of sliders mounted to said secondzipper tape.
 5. The article as recited in claim 1, wherein each of saidzipper tapes is in the form of a string zipper.
 6. The article asrecited in claim 1, wherein said first and second zipper tapes aredisposed closer to said second fold than to said first or third fold. 7.The article as recited in claim 1, wherein said first and second zippertapes are disposed closer to said first or third fold than to saidsecond fold.
 8. The article as recited in claim 1, wherein said articleis moving in a direction generally parallel to said second fold and aleading portion of said second fold is cut.
 9. The article as recited inclaim 1, wherein said first and second walls are cross sealed at regularspaced intervals to separate the space between said first and secondwalls into a first series of receptacles, and said third and fourthwalls are cross sealed at said regular spaced intervals to separate thespace between said third and fourth walls into a second series ofreceptacles.
 10. The article as recited in claim 9, wherein at least oneof said first series of receptacles and at least one of said secondseries of receptacles are filled with product.
 11. A method ofmanufacturing an article, comprising the following steps: extending aweb of bag making film under tension in a machine direction; joining afirst zipper tape to said web along a first zone of joinder generallyaligned with said machine direction; joining a second zipper tape tosaid web along a second zone of joinder generally parallel to said firstzone of joinder of said first zipper tape and spaced apart therefrom;and folding said web in first, second and third mutually parallel zonesextending in said machine direction, said first zone of folding beingdisposed between a first edge of said web and said first zipper tape,said second zone of folding being disposed between said first and secondzipper tapes, and said third zone of folding being disposed between saidsecond zipper tape and a second edge of said web.
 12. The method asrecited in claim 11, wherein said first and third zones of folding arefolded in a first direction and said second zone of folding is folded ina second direction opposite to said first direction.
 13. The method asrecited in claim 11, wherein said first and third zones of folding arefolded before said second zone of folding is folded.
 14. The method asrecited in claim 11, further comprising the following steps: joiningsaid first zipper tape to said web along a third zone of joindergenerally parallel to said first zone of joinder; and joining saidsecond zipper tape to said web along a fourth zone of joinder generallyparallel to said second zone of joinder.
 15. The method as recited inclaim 11, wherein said folded web reverses its direction along saidfolds to form a serpentine cross-sectional profile with first throughfourth walls, said second wall being disposed between said first andthird walls, said third wall being disposed between said second andfourth walls, a bottom of said first wall being connected to a bottom ofsaid second wall along said first fold, a top of said second wall beingconnected to a top of said third wall along said second fold, and abottom of said third wall being connected to a bottom of said fourthwall along said third fold,
 16. The method as recited in claim 11,further comprising the following steps: intermittently advancing saidweb in said machine direction; and cutting a leading portion of saidsecond zone of folding during said advancing step.
 17. The method asrecited in claim 15, further comprising the steps of cross sealing saidfirst and second walls at regular spaced intervals to separate the spacebetween said first and second walls into a first series of receptacles,and cross sealing said third and fourth walls at said regular spacedintervals to separate the space between said third and fourth walls intoa second series of receptacles.
 18. The method as recited in claim 17,further comprising the steps of filling respective receptacles of saidfirst and second series with product and then sealing and severing saidfilled receptacles.
 19. The method as recited in claim 18, wherein saidfilling step comprises filling product through open sections of saidfirst and second zipper tapes.
 20. The method as recited in claim 11,further comprising the steps of inserting a first multiplicity ofsliders on said first zipper tape and inserting a second multiplicity ofsliders on said second zipper tape.
 21. An article of manufacturecomprising: a web of bag making film folded under tension along first,second and third folds, said folded web reversing its direction alongsaid folds to form a serpentine cross-sectional profile with firstthrough fourth walls, said second wall being disposed between said firstand third walls, said third wall being disposed between said second andfourth walls, a bottom of said first wall being connected to a bottom ofsaid second wall along said first fold, a top of said second wall beingconnected to a top of said third wall along said second fold, and abottom of said third wall being connected to a bottom of said fourthwall along said third fold; and a zipper strip comprising a base havinga first portion joined to said second wall and a second portion joinedto said third wall, wherein said base is folded and wrapped around saidsecond fold of said web, said zipper strip further comprising first andsecond profiled closure members supported by said base and generallyparallel to each other, said first profiled closure member beingdisposed between said first and second walls of said web, and saidsecond profiled closure member being disposed between said third andfourth walls of said web.
 22. The article as recited in claim 21,further comprising second and third zipper strips, said second zipperstrip comprising a third profiled closure member interlocked with saidfirst profiled closure member, and said third zipper strip comprising afourth profiled closure member interlocked with said second profiledclosure member.
 23. The article as recited in claim 21, furthercomprising second and third zipper strips respectively joined to saidfirst and fourth walls of said web, said second zipper strip comprisinga third profiled closure member that is interlockable with said firstprofiled closure member, and said third zipper strip comprising a fourthprofiled closure member that is interlockable with said second profiledclosure member.
 24. The article as recited in claim 21, wherein saidzipper strip further comprises third and fourth profiled closure memberssupported by said base, said third profiled closure member beinginterlockable with said first profiled closure member, and said fourthprofiled closure member being interlockable with said second profiledclosure member.
 25. The article as recited in claim 21, wherein saidarticle is moving in a direction generally parallel to said second foldand a leading portion of said second fold is cut.
 26. The article asrecited in claim 21, wherein said first and second walls are crosssealed at regular spaced intervals to separate the space between saidfirst and second walls into a first series of receptacles, and saidthird and fourth walls are cross sealed at said regular spaced intervalsto separate the space between said third and fourth walls into a secondseries of receptacles.
 27. The article as recited in claim 26, whereinat least one of said first series of receptacles and at least one ofsaid second series of receptacles are filled with product.
 28. A methodof manufacturing an article, comprising the following steps: extending aweb of bag making film under tension in a machine direction; joining afirst zipper strip to said web along a first zone of joinder generallyaligned with said machine direction, said first zipper strip comprisinga base joined to said web, and first and second profiled closure memberssupported by said base and generally parallel to each other; and foldingsaid web and said base of said first zipper strip along a first zone offolding that overlaps a central portion said first zone of joinder, saidfirst and second profiled closure members being disposed on oppositesides of said first zone of folding.
 29. The method as recited in claim28, further comprising the steps of: joining a second zipper strip tosaid web along a second zone of joinder generally parallel to said firstzone of joinder and spaced apart therefrom, said second zipper stripbeing disposed between a first edge of said web and a first edge of saidbase of said first zipper strip; and joining a third zipper strip tosaid web along a third zone of joinder generally parallel to said firstzone of joinder and spaced apart therefrom, said third zipper stripbeing disposed between a second edge of said web and a second edge ofsaid base of said first zipper strip, wherein said second zipper stripcomprises a third profiled closure member interlockable with said firstprofiled closure member, and said third zipper strip comprises a fourthprofiled closure member interlockable with said second profiled closuremember.
 30. The method as recited in claim 29, further comprising thesteps of folding said web along second and third zones of folding thatare generally parallel to said first zone of folding, said first zone offolding being disposed between a first edge of said web and a first edgeof said base of said first zipper strip, and said second zone of foldingbeing disposed between a second edge of said web and a second edge ofsaid base of said first zipper strip.
 31. The method as recited in claim30, further comprising the steps of interlocking said third profiledclosure member with said first profiled closure member, and said fourthprofiled closure member with said second profiled closure member.
 32. Anintegrally formed hinged zippered structure comprising first and secondprofiled closure members, first and second hinge lines, a first webhaving one end connected to said first closure member and another endconnected to said first hinge line, a second web having one endconnected to said second closure member and another end connected tosaid second hinge line, and a third web having one end connected to saidfirst hinge line and the other end connected to said second hinge line.33. The zippered structure as recited in claim 32, further comprising athird profiled closure member interlocked with said first profiledclosure member, a fourth profiled closure member interlocked with saidsecond profiled closure member, a fourth web having one end connected tosaid third closure member and the other end connected to said firsthinge line, and a fifth web having one end connected to said fourthclosure member and the other end connected to said second hinge line.34. The zippered structure as recited in claim 32, further comprising afirst slider mounted to said first and third profiled closure members,and a second slider mounted to said second and fourth profiled closuremembers.
 35. An article of manufacture comprising a zippered structureas recited in claim 32 and a web of bag making film folded under tensionalong first, second and third folds, said folded web reversing itsdirection along said folds to form a serpentine cross-sectional profilewith first through fourth walls, said second wall being disposed betweensaid first and third walls, said third wall being disposed between saidsecond and fourth walls, a bottom of said first wall being connected toa bottom of said second wall along said first fold, a top of said secondwall being connected to a top of said third wall along said second fold,and a bottom of said third wall being connected to a bottom of saidfourth wall along said third fold, said third web having a first portionjoined to said second wall and a second portion joined to said thirdwall, said third web being folded and wrapped around said second fold ofsaid web of bag making film.
 36. The article as recited in claim 35,further comprising a first zipper part comprising a third closure memberand a first zipper flange, and a second zipper part comprising a fourthclosure member and a second zipper flange, said third closure memberbeing interlocked with said first closure member, said fourth closuremember being interlocked with said second closure member, said firstzipper flange having one end connected to said third closure member andanother end joined to said first wall, and said second zipper flangehaving one end connected to said fourth closure member and another endjoined to said fourth wall.
 37. A zippered structure comprising a zipperweb and first through fourth profiled closure members connected to saidzipper web, said first through fourth closure members being disposedgenerally in parallel with each other, said first closure member beinginterlocked with said second closure member, thereby forming a firstfold said first zipper web, and said third closure member beinginterlocked with said fourth closure member, thereby forming a secondfold in said zipper web, and further comprising a web of bag making filmjoined to a central portion of said zipper web extending from saidsecond closure member to said third closure member.
 38. The zipperedstructure as recited in claim 37, wherein said zipper web comprises afirst line of weakness disposed along said first fold and a second lineof weakness disposed between along said second fold.
 39. The zipperedstructure as recited in claim 37, wherein said web of bag making film isalso joined to said zipper web in first and second zones proximal tosaid first and fourth closure members respectively.
 40. A method ofmanufacturing an article, comprising the following steps: extending aweb of bag making film under tension in a machine direction; foldingsaid web in first, second and third mutually parallel zones extending insaid machine direction, said folded web reversing its direction alongsaid zones of folding to form a serpentine cross-sectional profile withfirst through fourth walls, said second wall being disposed between saidfirst and third walls, said third wall being disposed between saidsecond and fourth walls, a bottom of said first wall being connected toa bottom of said second wall along said first fold, a top of said secondwall being connected to a top of said third wall along said second fold,and a bottom of said third wall being connected to a bottom of saidfourth wall along said third fold; inserting at least a portion of afirst zipper tape between said first and second walls of said foldedweb; inserting at least a portion of a second zipper tape between saidthird and fourth walls of said folded web; joining said first zippertape to at least one of said first and second walls; and joining saidsecond zipper tape to at least one of said third and fourth walls. 41.The method as recited in claim 40, further comprising the followingsteps: intermittently advancing said web in said machine direction; andcutting a leading portion of said second zone of folding during saidadvancing step.
 42. The method as recited in claim 40, furthercomprising the steps of cross sealing said first and second walls atregular spaced intervals to separate the space between said first andsecond walls into a first series of receptacles, and cross sealing saidthird and fourth walls at said regular spaced intervals to separate thespace between said third and fourth walls into a second series ofreceptacles.
 43. The method as recited in claim 42, further comprisingthe steps of filling respective receptacles of said first and secondseries with product and then sealing and severing said filledreceptacles.
 44. The method as recited in claim 40, further comprisingthe steps of inserting a first multiplicity of sliders on said firstzipper tape and inserting a second multiplicity of sliders on saidsecond zipper tape.
 45. A machine for forming, filling and sealing afolded web of bag making film, said folded web having a serpentinecross-sectional profile comprising first and second folded portions inrespective upright positions and open at the tops, and a centralinverted folded portion extending in a machine direction, said centralinverted folded portion connecting said first folded portion to saidsecond folded portion, wherein said machine comprises: an upright saddlehaving a generally constant profile in said machine direction, whereinsaid central inverted folded portion of said web is supported by saidsaddle and slides along said saddle as said web advances in said machinedirection. means for cross sealing said first and second folded portionsof said web at regular spaced intervals to form respective first andsecond series of open receptacles; means for filling successivereceptacles of said first and second series concurrently; and means forsealing successive filled receptacles of said first and second seriesclosed.
 46. The machine as recited in claim 45, further comprising meansfor attaching first and second zipper tapes (with or without slidersinserted thereon) to said web of bag making film.
 47. The machine asrecited in claim 46, wherein said zipper tapes comprises zipper flanges,and said zipper tape attaching means comprise first through fourth heatsealing bars for sealing said zipper flanges to said web of bag makingfilm, and first and second separating plates for separating said zipperflanges of said respective first and second zipper tapes during sealingto prevent seal-through.
 48. The machine as recited in claim 46, whereinsaid zipper tapes are of the type that do not have zipper flanges, andsaid zipper tape attaching means comprise first through fourth heatsealing bars for sealing said zipper tapes to said web of bag makingfilm, and first and second separating plates for separating the zipperprofiles of said respective first and second zipper tapes during sealingto prevent seal-through.
 49. An article of manufacture comprising: a webof bag making film folded under tension along first, second and thirdfolds, said folded web reversing its direction along said folds to forma serpentine cross-sectional profile with first through fourth walls,said second wall being disposed between said first and third walls, saidthird wall being disposed between said second and fourth walls, a bottomof said first wall being connected to a bottom of said second wall alongsaid first fold, a top of said second wall being connected to a top ofsaid third wall along said second fold, and a bottom of said third wallbeing connected to a bottom of said fourth wall along said third fold; afirst zipper tape having a portion disposed between said first andsecond walls of said web, and joined to at least one of said first andsecond walls; and a second zipper tape having a portion disposed betweensaid third and fourth walls of said web, and joined to at least one ofsaid third and fourth walls, wherein each of said first and secondzipper tapes comprises first and second mutually interlockable portionsin an interlocked state.
 50. The article of manufacture as recited inclaim 49, further comprises a first peel seal above said first zippertape and a second peel seal above said second zipper tape.
 51. Thearticle of manufacture as recited in claim 49, further comprises a firstpeel seal below said first zipper tape and a second peel seal below saidsecond zipper tape.
 52. The method as recited in claim 18, wherein saidfilling step comprises filling product through openings between theunsealed sides of said first and second zipper tapes and the opposingportions of said web of bag making film.
 53. The method as recited inclaim 18, wherein said filling step comprises opening the respectivereceptacles of said first and second series by moving sliders mounted tothe zippers of said receptacles and filling product through said openzippers.